1. Field of the Invention
The present invention relates to a recording apparatus for printing at high speed by emitting ink onto a cloth to be recorded. More specifically, the present invention relates to a recording apparatus capable of high speed printing and not wasting ink in which drying of an ink jet head is prevented even when inks of different properties are used.
2. Description of the Background Art
Methods of industrial textile printing for dying cloth include screen printing, roller printing and transfer printing. Each of these printing methods is a printing technique completed by organic combination of a series of steps including planning of design pattern, engraving or processing of the design pattern, production of starch and preparation of cloth. Such printing technique requires four steps as well as high skill. Therefore, printing of a cloth requires time and labor, and therefore, considerable cost. Further, such printing methods are not necessarily suitable for producing various different types of products in small amount.
Recently, ink jet printing method, which is considered suitable for producing various types of products in small amount has been practically used. Ink jet printing method includes a method of printing using inks of four colors, that is, yellow (Y), magenta (M), cyan (C) and black (B) as in a printer for a personal computer, a method using eight colors including red (R), green (G), blue (B) and a special color in addition to Y, M, C and B, and a method using a total of ten colors.
Further, in order to attain realer printing, density of printing ink is changed in accordance with the design to be printed, so that various tones are realized.
Generally, in a nozzle of a head which is not frequently used, ink dries in the ink emission hole and the vicinity thereof, so that the ink comes to have higher viscosity. This leads to the problems of failure in ink emission or in stability of the direction of ink emission. As already described, when wider variety of inks are used, frequency of use per unit time of each type of ink is reduced, making the problem more serious.
In order to prevent ink viscosity from being increased, Japanese Patent Laying-Open No. 59-7053 discloses an ink jet recording apparatus in which ink of which viscosity has been increased is emitted to an ink receiving equipment at a portion other than the printing portion, at the time of power on. This smoothes subsequent ink emission, ensuring satisfactory printing.
Japanese Patent Laying-Open No. 62-116153 discloses a recording apparatus in which whether ink is to be emitted or not is determined dependent on atmospheric moisture, and when the moisture is lower than a prescribed value, ink is emitted. This prevents increase in ink viscosity.
In an ink jet recording apparatus disclosed in Japanese Patent Laying-Open No. 63-260450, ink emission control is performed dependent on moisture and temperature of the atmosphere. This prevents increase in ink viscosity.
However, in any of the above described three apparatuses, a head is moved to the ink receiving equipment, stopped there and ink is emitted at a time point when it is determined that intermission is necessary. Therefore, much time is consumed for ink emission. Further, inks of all types are emitted simultaneously. This results in increased size of the ink receiving equipment. Further, inks are wasted, as inks of which viscosity are not increased are simultaneously emitted.
Further, a mechanism for preventing overflow of ink from the ink receiving equipment is also important.